This disclosure relates to a fan section for a gas turbine engine. More particularly, the application relates to a nose cone noise attenuation feature.
A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustor section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
One type of gas turbine engine includes a fan drive gear system having a fan section with relatively large diameter fan blades. In high bypass ratio gas turbine applications using a fan drive gear system, fan noise can be a major source of overall engine noise. Higher bypass ratios mean larger fans with respect to the engine core components, and lower exhaust stream velocities exposing the fan noise sources more than other sources. Acoustic liners have been used in the fan nacelle upstream from the fan to reduce fan noise.